A 1 train rider was punched and stabbed in the back yesterday afternoon in Harlem. One account suggests that the victim had been trying to calm his attacker down, while other reports say the pair were fighting.

The incident occurred on a train that was pulling into the 145th Street station at Broadway. According to NBC New York, "Two men reportedly clashed on the 1 train as it was approaching 145th Street and Broadway just before 5 p.m., and when the train pulled into the station, the fight carried over to the platform, where the 30-year-old victim was stabbed in the back, police said. "

An NYPD spokesman told us the victim said he was punched twice in the face and then stabbed in the back three times.

However, the Daily News's sources say, "The 30-year-old victim was trying to calm down a stranger — who got visibly agitated about being on a stalled No 1. train just shy of the 145th St. station... Instead of taking it easy, the suspect whipped out a sharp object and stabbed the victim twice in the lower back around 4:30 p.m., authorities said." A source said, "Nothing preceded it."

Police are investigating the incident. At this point, the suspect is described as being 6'2" and 180 pounds, wearing a "green jacket, hat and glasses."